Answer:
Choropleth Map
This is used to show population density in countries of the world specifically with its color variation used to show the differences in population within that region.
Trees 3-5 percent causing an increase in temperature and were dying from droughts that happened leaving dehydrated and dead vegetation and so, had no way of food to survive as many say "they did this to themselves" which I slightly agree with but that is some of what the Mayans lacked.
It gives electrons because they are both oppositely charged